Product details


Vs (Min) (V) 4 Vs (Max) (V) 40 Operating temperature range (C) 0 to 70 open-in-new Find other Frequency converters

Package | Pins | Size

PDIP (P) 8 93 mm² 9.81 x 9.43 open-in-new Find other Frequency converters


  • Ensured Linearity 0.01% Maximum
  • Improved Performance in Existing Voltage-to-
    Frequency Conversion Applications
  • Split or Single-Supply Operation
  • Operates on Single 5-V Supply
  • Pulse Output Compatible With All Logic Forms
  • Excellent Temperature Stability: ±50 ppm/°C
  • Low Power Consumption: 15 mW Typical at 5 V
  • Wide Dynamic Range, 100 dB Minimum at 10-kHz
    Full Scale Frequency
  • Wide Range of Full Scale Frequency:
    1 Hz to 100 kHz
  • Low-Cost
open-in-new Find other Frequency converters


The LMx31 family of voltage-to-frequency converters are ideally suited for use in simple low-cost circuits for analog-to-digital conversion, precision frequency-to-voltage conversion, long-term integration, linear frequency modulation or demodulation, and many other functions. The output when used as a voltage-to-frequency converter is a pulse train at a frequency precisely proportional to the applied input voltage. Thus, it provides all the inherent advantages of the voltage-to-frequency conversion techniques, and is easy to apply in all standard voltage-to-frequency converter applications.

Further, the LMx31A attain a new high level of accuracy versus temperature which could only be attained with expensive voltage-to-frequency modules. Additionally the LMx31 are ideally suited for use in digital systems at low power supply voltages and can provide low-cost analog-to-digital conversion in microprocessor-controlled systems. And, the frequency from a battery-powered voltage-to-frequency converter can be easily channeled through a simple photo isolator to provide isolation against high common-mode levels.

The LMx31 uses a new temperature-compensated band-gap reference circuit, to provide excellent accuracy over the full operating temperature range, at power supplies as low as 4 V. The precision timer circuit has low bias currents without degrading the quick response necessary for 100-kHz voltage-to-frequency conversion. And the output are capable of driving 3 TTL loads, or a high-voltage output up to 40 V, yet is short-circuit-proof against VCC.

open-in-new Find other Frequency converters

Technical documentation

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Design tools & simulation

SPICE-based analog simulation program
TINA-TI TINA-TI provides all the conventional DC, transient and frequency domain analysis of SPICE and much more. TINA has extensive post-processing capability that allows you to format results the way you want them. Virtual instruments allow you to select input waveforms and probe circuit nodes voltages (...)
document-generic User guide

Reference designs

Comparator with Hysteresis Reference Design
TIPD144 This TI Verified Design implements a comparator with hysteresis.  Comparators are used to differentiate between two different signal levels.  For example, a comparator may differentiate between an over temperature and normal temperature condition.  Noise or signal variation at the (...)
document-generic Schematic document-generic User guide

CAD/CAE symbols

Package Pins Download
PDIP (P) 8 View options

Ordering & quality

Support & training

TI E2E™ forums with technical support from TI engineers

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​​​​​​​


Related videos